YOKOGAWA DL9040L

App-17
IM 701310-01E
Appendix
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App
Index
Appendix 4 Waveform Parameter Integrals and
Derivatives
Differentiation (DIFF)
The computation of the first order and second order differentiation uses the 5th order
Lagrange interpolation formula to derive a point of data from the 5 points around the
point. The data f0 to fn and I0 to In corresponde to sampling time x0 to xn.
Point xk fk'= [fk-2 – 8fk-1 + 8fk+1 – fk+2]
1
12h
h = ∆x is the sampling interval (sec) (example h = 200 × 10
–6
at 5 kHz)
Integration (INTEG)
Point x0 I
0
= 0
Point x1 I
1
= (f
0
+ f
1
)h
Point x2 I
2
= (f
0
+ f
1
)h + (f
1
+ f
2
)h = I
1
+ (f
1
+ f
2
)h
Point xn I
n
= I
n-1
+ (f
n-1
+ f
n
)h
1
2
1
2
1
2
1
2
1
2